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- Antoniou, Antonis C., et al.
(författare)
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Common alleles at 6q25.1 and 1p11.2 are associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers
- 2011
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 20:16, s. 3304-3321
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Tidskriftsartikel (refereegranskat)abstract
- Two single nucleotide polymorphisms (SNPs) at 6q25.1, near the ESR1 gene, have been implicated in the susceptibility to breast cancer for Asian (rs2046210) and European women (rs9397435). A genome-wide association study in Europeans identified two further breast cancer susceptibility variants: rs11249433 at 1p11.2 and rs999737 in RAD51L1 at 14q24.1. Although previously identified breast cancer susceptibility variants have been shown to be associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers, the involvement of these SNPs to breast cancer susceptibility in mutation carriers is currently unknown. To address this, we genotyped these SNPs in BRCA1 and BRCA2 mutation carriers from 42 studies from the Consortium of Investigators of Modifiers of BRCA1/2. In the analysis of 14 123 BRCA1 and 8053 BRCA2 mutation carriers of European ancestry, the 6q25.1 SNPs (r(2) = 0.14) were independently associated with the risk of breast cancer for BRCA1 mutation carriers [ hazard ratio (HR) = 1.17, 95% confidence interval (CI): 1.11-1.23, P-trend = 4.5 x 10(-9) for rs2046210; HR = 1.28, 95% CI: 1.18-1.40, P-trend = 1.3 x 10(-8) for rs9397435], but only rs9397435 was associated with the risk for BRCA2 carriers (HR = 1.14, 95% CI: 1.01-1.28, P-trend = 0.031). SNP rs11249433 (1p11.2) was associated with the risk of breast cancer for BRCA2 mutation carriers (HR = 1.09, 95% CI: 1.02-1.17, P-trend = 0.015), but was not associated with breast cancer risk for BRCA1 mutation carriers (HR = 0.97, 95% CI: 0.92-1.02, P-trend = 0.20). SNP rs999737 (RAD51L1) was not associated with breast cancer risk for either BRCA1 or BRCA2 mutation carriers (P-trend = 0.27 and 0.30, respectively). The identification of SNPs at 6q25.1 associated with breast cancer risk for BRCA1 mutation carriers will lead to a better understanding of the biology of tumour development in these women.
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| 2. |
- Brohet, Richard M., et al.
(författare)
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Oral contraceptives and breast cancer risk in the international BRCA1/2 carrier cohort study: A report from EMBRACE, GENEPSO, GEO-HEBON, and the IBCCS Collaborating Group
- 2007
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Ingår i: Journal of Clinical Oncology. - 1527-7755. ; 25:25, s. 3831-3836
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Earlier studies have shown that endogenous gonadal hormones play an important role in the etiology of breast cancer among BRCA1/ 2 mutation carriers. So far, little is known about the safety of exogenous hormonal use in mutation carriers. In this study, we examined the association between oral contraceptive use and risk of breast cancer among BRCA1/ 2 carriers. Patients and Methods In the International BRCA1/ 2 Carrier Cohort study ( IBCCS), a retrospective cohort of 1,593 BRCA1/ 2 mutation carriers was analyzed with a weighted Cox regression analysis. Results We found an increased risk of breast cancer for BRCA1/ 2 mutation carriers who ever used oral contraceptives ( adjusted hazard ratio [ HR] = 1.47; 95% CI, 1.16 to 1.87). HRs did not vary according to time since stopping use, age at start, or calendar year at start. However, a longer duration of use, especially before first full- term pregnancy, was associated with an increased risk of breast cancer for both BRCA1 and BRCA2 mutation carriers ( 4 or more years of use before first full-term pregnancy: HR = 1.49 [ 95% CI, 1.05 to 2.11] for BRCA1 carriers and HR = 2.58 [ 95% CI, 1.21 to 5.49] for BRCA2 carriers). Conclusion No evidence was found among BRCA1/ 2 mutation carriers that current use of oral contraceptives is associated with risk of breast cancer more strongly than is past use, as is found in the general population. However, duration of use, especially before first full- term pregnancy, may be associated with an increasing risk of breast cancer among both BRCA1 and BRCA2 mutation carriers.
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| 4. |
- Schrijver, Lieske H, et al.
(författare)
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Oral contraceptive use and ovarian cancer risk for BRCA1/2 mutation carriers : an international cohort study
- 2021
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Ingår i: American Journal of Obstetrics and Gynecology. - : Elsevier BV. - 1097-6868 .- 0002-9378. ; 225:1, s. 1-51
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Ovarian cancer risk in BRCA1 and BRCA2 mutation carriers has been shown to decrease with longer duration of oral contraceptive preparations (OCPs) use. While the effects of OCPs in the general population are well established (∼50% reduction), the estimated risk reduction in mutation carriers is much less precise due to potential bias and small sample sizes. In addition, only a few studies have examined the associations between duration of use, time since last use, starting age, and calendar year of start with risk of ovarian cancer.OBJECTIVE(S): To investigate in more detail the associations between various characteristics of OCP use and risk of ovarian cancer, to provide health care providers and carriers with better risk estimates.STUDY DESIGN: In this international retrospective study, ovarian cancer risk associations were assessed using OCP data on 3,989 BRCA1 and 2,445 BRCA2 mutation carriers. Age-dependent weighted Cox regression analyses were stratified by study and birth cohort and included breast cancer diagnosis as covariate. To minimize survival bias, analyses were left-truncated at 5 years before baseline questionnaire. Separate analysis were conducted for each of the aspects of OCP use and in a multivariate analysis including all these aspects. In addition, the analysis of duration of OCP use was stratified by recency of use.RESULTS: OCPs were less often used by mutation carriers who were diagnosed with ovarian cancer (Ever use: BRCA1 58.6%, BRCA2 53.5%) than by unaffected carriers (Ever use: BRCA1 88.9%, BRCA2 80.7%. The median duration of use was 7 years for both BRCA1 and BRCA2 carriers who developed ovarian cancer, and 9 and 8 years for ovarian cancer unaffected BRCA1 and BRCA2 carriers, respectively. For BRCA1 mutation carriers univariate analyses showed that both a longer duration of OCP use and more recent use of OCPs were inversely associated with risk of ovarian cancer. However, in multivariate analyses including duration of use, age at first use and time since last use, duration of use proved to be the prominent protective factor (compared with <5 years, 5-9 years HR=0.67;95%CI 0.40-1.12, 10+ years HR=0.37;95%CI 0.19-0.73; ptrend=0.008). The inverse association between duration of use and ovarian cancer risk persisted for more than 15 years (Duration of ≥10 years; BRCA1: <15 years since last use: HR=0.24 95%CI 0.14-0.43, 15+ years since last use: HR 0.56 95%CI 0.18-0.59). Univariate results for BRCA2 mutation carriers were similar, but due to limit sample size inconclusive.CONCLUSION: For BRCA1 mutation carriers, a longer duration of OCP use is associated with a greater reduction of ovarian cancer risk and the protection is long term.
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